Configuring IP SLAs UDP Jitter Operations
This document describes how to configure an IP Service Level Agreements (SLAs) UDP jitter operation to
analyze round-trip delay, one-way delay, one-way jitter, one-way packet loss, and connectivity in networks
that carry UDP traffic in IPv4 or IPv6 networks. This module also demonstrates how the data gathered using
the UDP jitter operation can be displayed and analyzed using Cisco software commands.
• Finding Feature Information, page 1
• Prerequisites, page 1
• Information About IP SLAs UDP Jitter Operations, page 2
• How to Configure IP SLAs UDP Jitter Operations, page 3
• Configuration Examples for IP SLAs UDP Jitter Operations, page 13
• Additional References, page 13
• Feature Information for IP SLAs UDP Jitter Operations, page 14
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature
information and caveats, see the release notes for your platform and software release. To find information
about the features documented in this module, and to see a list of the releases in which each feature is supported,
see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support.
To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites
• Time synchronization, such as that provided by NTP, is required between the source and the target device
in order to provide accurate one-way delay (latency) measurements. To configure NTP on the source
and target devices, perform the tasks in the “Performing Basic System Management” chapter of the
Network Management Configuration Guide. Time synchronization is not required for the one-way jitter
and packet loss measurements, however. If the time is not synchronized between the source and target
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Configuring IP SLAs UDP Jitter Operations
Information About IP SLAs UDP Jitter Operations
devices, one-way jitter and packet loss data will be returned, but values of “0” will be returned for the
one-way delay measurements provided by the UDP jitter operation.
• Before configuring any IP SLAs application, you can use the show ip sla application command to verify
that the operation type is supported on your software image.
Information About IP SLAs UDP Jitter Operations
IP SLAs UDP Jitter Operation
The IP SLAs UDP jitter operation was primarily designed to diagnose network suitability for real-time traffic
applications such as voice over IP (VoIP), video over IP, or real-time conferencing.
Jitter means inter-packet delay variance. When multiple packets are sent consecutively from source to
destination, for example, 10 ms apart, and if the network is behaving ideally, the destination should be receiving
them 10 ms apart. But if there are delays in the network (like queuing, arriving through alternate routes, and
so on) the arrival delay between packets might be greater than or less than 10 ms. Using this example, a
positive jitter value indicates that the packets arrived greater than 10 ms apart. If the packets arrive 12 ms
apart, then positive jitter is 2 ms; if the packets arrive 8 ms apart, then negative jitter is 2 ms. For delay-sensitive
networks like VoIP, positive jitter values are undesirable, and a jitter value of 0 is ideal.
However, the IP SLAs UDP jitter operation does more than just monitor jitter. As the UDP jitter operation
includes the data returned by the IP SLAs UDP operation, the UDP jitter operation can be used as a multipurpose
data gathering operation. The packets IP SLAs generates carry packet-sending and receiving sequence
information, and sending and receiving time stamps from the source and the operational target. Based on this
information, UDP jitter operations are capable of measuring the following:
• Per-direction jitter (source to destination and destination to source)
• Per-direction packet loss
• Per-direction delay (one-way delay)
• Round-trip delay (average round-trip time)
As the paths for sending and receiving data may be different (asymmetric), the per-direction data allows you
to more readily identify where congestion or other problems are occurring in the network.
The UDP jitter operation functions by generating synthetic (simulated) UDP traffic. The UDP jitter operation
sends N UDP packets, each of size S, T milliseconds apart, from a source device to a target device, at a given
frequency of F. By default, ten packet frames (N), each with a payload size of 10 bytes (S), are generated
every 10 ms (T), and the operation is repeated every 60 seconds (F). Each of these parameters is
user-configurable, so as to best simulate the IP service you are providing, or want to provide, as shown in the
table below.
Table 1: UDP Jitter Operation Parameters
UDP Jitter Operation Parameter
Default
Configured Using:
Number of packets (N)
10 packets
udp-jitter command, num-packets
option
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Configuring IP SLAs UDP Jitter Operations
How to Configure IP SLAs UDP Jitter Operations
UDP Jitter Operation Parameter
Default
Configured Using:
Payload size per packet (S)
32 bytes
request-data-size command
Time between packets, in
milliseconds (T)
20 ms
udp-jitter command, interval
option
Elapsed time before the operation 60 seconds
repeats, in seconds (F)
frequency (IP SLA) command
The IP SLAs operations function by generating synthetic (simulated) network traffic. A single IP SLAs
operation (for example, IP SLAs operation 10) will repeat at a given frequency for the lifetime of the operation.
How to Configure IP SLAs UDP Jitter Operations
Configuring the IP SLAs Responder on the Destination Device
A responder should not configure a permanent port for the same sender. If the responder configures a
permanent port for the same sender, even if the packets are successfully sent (no timeout or packet-loss
issues), the jitter values will be zero.
Note
SUMMARY STEPS
1. enable
2. configure terminal
3. Do one of the following:
• ip sla responder
• ip sla responder udp-echo ipaddress
ip-address
port port
4. exit
DETAILED STEPS
Step 1
Command or Action
Purpose
enable
Enables privileged EXEC mode.
Example:
• Enter your password if prompted.
Device> enable
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Configuring and Scheduling a UDP Jitter Operation on the Source Device
Step 2
Command or Action
Purpose
configure terminal
Enters global configuration mode.
Example:
Device# configure terminal
Step 3
Do one of the following:
• ip sla responder
• ip sla responder udp-echo ipaddress
ip-address port port
Example:
(Optional) Temporarily enables IP SLAs Responder functionality
on a Cisco device in response to control messages from the
source.
(Optional) Required only if protocol control is disabled on the
source. Enables IP SLAs responder functionality on the specified
IP address and port.
• Protocol control is enabled by default.
Device(config)# ip sla responder
Example:
Device(config)# ip sla responder udp-echo
ipaddress 172.29.139.132 port 5000
Step 4
(Optional) Exits global configuration mode and returns to
privileged EXEC mode.
exit
Example:
Device(config)# exit
Configuring and Scheduling a UDP Jitter Operation on the Source Device
Perform only one of the following tasks:
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Configuring and Scheduling a UDP Jitter Operation on the Source Device
Configuring a Basic UDP Jitter Operation on the Source Device
SUMMARY STEPS
1. enable
2. configure terminal
operation-number
3. ip sla
4. udp-jitter {destination-ip-address | destination-hostname} destination-port [source-ip {ip-address |
hostname}] [source-port port-number] [control {enable | disable}] [num-packets number-of-packets]
[interval interpacket-interval]
5. frequency seconds
6. end
7. show ip sla configuration [operation-number]
DETAILED STEPS
Step 1
Command or Action
Purpose
enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Example:
Device> enable
Step 2
configure terminal
Enters global configuration mode.
Example:
Device# configure terminal
Step 3
ip sla
operation-number
Begins configuration for an IP SLAs operation and enters
IP SLA configuration mode.
Example:
Device(config)# ip sla 10
Step 4
udp-jitter {destination-ip-address |
destination-hostname} destination-port [source-ip
{ip-address | hostname}] [source-port port-number]
[control {enable | disable}] [num-packets
number-of-packets] [interval interpacket-interval]
Configures the IP SLAs operation as a UDP jitter operation
and enters UDP jitter configuration submode.
• Use the control disable keyword combination only
if you disable the IP SLAs control protocol on both
the source and destination devices.
Example:
Device(config-ip-sla)# udp-jitter 172.29.139.134
5000
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Configuring and Scheduling a UDP Jitter Operation on the Source Device
Step 5
Command or Action
Purpose
frequency seconds
(Optional) Sets the rate at which a specified IP SLAs
operation repeats.
Example:
Device(config-ip-sla-jitter)# frequency 30
Step 6
Returns to privileged EXEC mode.
end
Example:
Device(config-ip-sla-jitter)# end
Step 7
show ip sla configuration [operation-number]
(Optional) Displays configuration values including all
defaults for all IP SLAs operations or a specified operation.
Example:
Device# show ip sla configuration 10
What to Do Next
To configure the percentile option for your operation, see the “Configuring the IP SLAs - Percentile Support
for Filtering Outliers” module.
Configuring a UDP Jitter Operation with Additional Characteristics
Note
• The IP SLAs UDP jitter operation does not support the IP SLAs History feature (statistics history
buckets) because of the large data volume involved with UDP jitter operations. This means that the
following commands are not supported for UDP jitter operations: history buckets-kept, history
filter, history lives-kept, samples-of-history-kept, and show ip sla history.
• The MIB used by IP SLAs (CISCO-RTTMON-MIB) limits the hours-of-statistics kept for the UDP
jitter operation to two hours. Configuring a larger value using the history hours-of-statisticshours
global configuration change will not increase the value beyond two hours. However, the Data
Collection MIB can be used to collect historical data for the operation. For information, see the
CISCO-DATA-COLLECTION-MIB at http://www.cisco.com/go/mibs ).
Before You Begin
Before configuring a UDP jitter operation on the source device, the IP SLAs Responder must be enabled on
the target device (the operational target). The IP SLAs Responder is available only on Cisco IOS software-based
devices. To enable the Responder, perform the task in the “Configuring the IP SLAs Responder on the
Destination Device” section.
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Configuring IP SLAs UDP Jitter Operations
Configuring and Scheduling a UDP Jitter Operation on the Source Device
SUMMARY STEPS
1. enable
2. configure terminal
operation-number
3. ip sla
4. udp-jitter {destination-ip-address | destination-hostname} destination-port [source-ip {ip-address |
hostname}] [source-port port-number] [control {enable | disable}] [num-packets number-of-packets]
[interval interpacket-interval]
5. history distributions-of-statistics-kept size
6. history enhanced [interval seconds] [buckets number-of-buckets]
7. frequency seconds
8. history hours-of-statistics-kept hours
9. owner owner-id
10. request-data-size bytes
11. history statistics-distribution-interval milliseconds
12. tag text
13. threshold milliseconds
14. timeout milliseconds
15. Do one of the following:
• tos number
• traffic-class number
16. flow-label number
17. verify-data
18. vrf vrf-name
19. end
20. show ip sla configuration [operation-number]
DETAILED STEPS
Step 1
Command or Action
Purpose
enable
Enables privileged EXEC mode.
Example:
• Enter your password if prompted.
Device> enable
Step 2
configure terminal
Enters global configuration mode.
Example:
Device# configure terminal
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Configuring and Scheduling a UDP Jitter Operation on the Source Device
Command or Action
Step 3
ip sla
operation-number
Purpose
Begins configuration for an IP SLAs operation and enters
IP SLA configuration mode.
Example:
Device(config)# ip sla 10
Step 4
udp-jitter {destination-ip-address |
destination-hostname} destination-port [source-ip
{ip-address | hostname}] [source-port port-number]
[control {enable | disable}] [num-packets
number-of-packets] [interval interpacket-interval]
Configures the IP SLAs operation as a UDP jitter operation
and enters UDP jitter configuration submode.
• Use the control disable keyword combination only if
you disable the IP SLAs control protocol on both the
source and target devices.
Example:
Device(config-ip-sla)# udp-jitter 172.29.139.134
5000
Step 5
history distributions-of-statistics-kept size
(Optional) Sets the number of statistics distributions kept
per hop during an IP SLAs operation.
Example:
Device(config-ip-sla-jitter)# history
distributions-of-statistics-kept 5
Step 6
history enhanced [interval seconds] [buckets
number-of-buckets]
(Optional) Enables enhanced history gathering for an IP
SLAs operation.
Example:
Device(config-ip-sla-jitter)# history enhanced
interval 900 buckets 100
Step 7
frequency seconds
(Optional) Sets the rate at which a specified IP SLAs
operation repeats.
Example:
Device(config-ip-sla-jitter)# frequency 30
Step 8
history hours-of-statistics-kept hours
(Optional) Sets the number of hours for which statistics are
maintained for an IP SLAs operation.
Example:
Device(config-ip-sla-jitter)# history
hours-of-statistics-kept 4
Step 9
owner owner-id
Example:
Device(config-ip-sla-jitter)# owner admin
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(Optional) Configures the Simple Network Management
Protocol (SNMP) owner of an IP SLAs operation.
Configuring IP SLAs UDP Jitter Operations
Configuring and Scheduling a UDP Jitter Operation on the Source Device
Step 10
Command or Action
Purpose
request-data-size bytes
(Optional) Sets the protocol data size in the payload of an
IP SLAs operation's request packet.
Example:
Device(config-ip-sla-jitter)# request-data-size
64
Step 11
history statistics-distribution-interval milliseconds (Optional) Sets the time interval for each statistics
distribution kept for an IP SLAs operation.
Example:
Device(config-ip-sla-jitter)# history
statistics-distribution-interval 10
Step 12
tag text
(Optional) Creates a user-specified identifier for an IP SLAs
operation.
Example:
Device(config-ip-sla-jitter)# tag
TelnetPollServer1
Step 13
threshold milliseconds
Example:
(Optional) Sets the upper threshold value for calculating
network monitoring statistics created by an IP SLAs
operation.
Device(config-ip-sla-jitter)# threshold 10000
Step 14
timeout milliseconds
(Optional) Sets the amount of time an IP SLAs operation
waits for a response from its request packet.
Example:
Device(config-ip-sla-jitter)# timeout 10000
Step 15
Do one of the following:
• tos number
• traffic-class number
(Optional) In an IPv4 network only, defines the ToS byte in
the IPv4 header of an IP SLAs operation.
or
(Optional) In an IPv6 network only, defines the traffic class
byte in the IPv6 header for a supported IP SLAs operation.
Example:
Device(config-ip-sla-jitter)# tos 160
Example:
Device(config-ip-sla-jitter)# traffic-class 160
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Configuring IP SLAs UDP Jitter Operations
Scheduling IP SLAs Operations
Step 16
Command or Action
Purpose
flow-label number
(Optional) In an IPv6 network only, defines the flow label
field in the IPv6 header for a supported IP SLAs operation.
Example:
Device(config-ip-sla-jitter)# flow-label 112233
Step 17
verify-data
(Optional) Causes an IP SLAs operation to check each reply
packet for data corruption.
Example:
Device(config-ip-sla-jitter)# verify-data
Step 18
vrf vrf-name
Example:
(Optional) Allows monitoring within Multiprotocol Label
Switching (MPLS) Virtual Private Networks (VPNs) using
IP SLAs operations.
Device(config-ip-sla-jitter)# vrf vpn-A
Step 19
Returns to privileged EXEC mode.
end
Example:
Device(config-ip-sla-jitter)# end
Step 20
show ip sla configuration [operation-number]
(Optional) Displays configuration values including all
defaults for all IP SLAs operations or a specified operation.
Example:
Device# show ip sla configuration 10
What to Do Next
To configure the percentile option for your operation, see the “Configuring the IP SLAs - Percentile Support
for Filtering Outliers” module.
Scheduling IP SLAs Operations
Note
• All IP SLAs operations to be scheduled must be already configured.
• The frequency of all operations scheduled in a multioperation group must be the same.
• The list of one or more operation ID numbers to be added to a multioperation group is limited to a
maximum of 125 characters in length, including commas (,).
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Configuring IP SLAs UDP Jitter Operations
Scheduling IP SLAs Operations
SUMMARY STEPS
1. enable
2. configure terminal
3. Do one of the following:
• ip sla schedule operation-number [life {forever | seconds}] [start-time {[hh:mm:ss] [month day
| day month] | pending | now | after hh:mm:ss}] [ageout seconds] [recurring]
• ip sla group schedule group-operation-number operation-id-numbers {schedule-period
schedule-period-range | schedule-together} [ageout seconds] [frequency
group-operation-frequency] [life {forever | seconds}] [start-time{hh:mm[:ss] [month day | day
month] | pending | now | after hh:mm[:ss]}]
4. exit
5. show ip sla group schedule
6. show ip sla configuration
DETAILED STEPS
Step 1
Command or Action
Purpose
enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Example:
Device> enable
Step 2
Enters global configuration mode.
configure terminal
Example:
Device# configure terminal
Step 3
Do one of the following:
• ip sla schedule operation-number [life {forever | seconds}]
[start-time {[hh:mm:ss] [month day | day month] | pending |
now | after hh:mm:ss}] [ageout seconds] [recurring]
• ip sla group schedule group-operation-number
operation-id-numbers {schedule-period
schedule-period-range | schedule-together} [ageout seconds]
[frequency group-operation-frequency] [life {forever |
seconds}] [start-time{hh:mm[:ss] [month day | day month] |
pending | now | after hh:mm[:ss]}]
• Configures the scheduling parameters for
an individual IP SLAs operation.
• Specifies an IP SLAs operation group
number and the range of operation numbers
for a multioperation scheduler.
Example:
Device(config)# ip sla schedule 10 life forever start-time
now
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Configuring IP SLAs UDP Jitter Operations
Scheduling IP SLAs Operations
Command or Action
Purpose
Example:
Device(config)# ip sla group schedule 1 3,4,6-9 life
forever start-time now
Step 4
Exits to privileged EXEC mode.
exit
Example:
Device(config)# exit
Step 5
show ip sla group schedule
(Optional) Displays IP SLAs group schedule
details.
Example:
Device# show ip sla group schedule
Step 6
show ip sla configuration
(Optional) Displays IP SLAs configuration
details.
Example:
Device# show ip sla configuration
Troubleshooting Tips
• If the IP SLAs operation is not running and not generating statistics, add the verify-data command to
the configuration of the operation (while configuring in IP SLA configuration mode) to enable data
verification. When data verification is enabled, each operation response is checked for corruption. Use
the verify-data command with caution during normal operations because it generates unnecessary
overhead.
• Use the debug ip sla trace and debug ip sla error commands to help troubleshoot issues with an IP
SLAs operation.
What to Do Next
To add proactive threshold conditions and reactive triggering for generating traps (or for starting another
operation) to an IP SLAs operation, see the “Configuring Proactive Threshold Monitoring” section.
To display and interpret the results of an IP SLAs operation, use the show ip sla statistics command. Check
the output for fields that correspond to criteria in your service level agreement to determine whether the service
metrics are acceptable.
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Configuring IP SLAs UDP Jitter Operations
Configuration Examples for IP SLAs UDP Jitter Operations
Configuration Examples for IP SLAs UDP Jitter Operations
Example Configuring a UDP Jitter Operation
In the following example, two operations are configured as UDP jitter operations, with operation 2 starting
five seconds after the first operation. Both operations will run indefinitely.
ip sla 1
udp-jitter 20.0.10.3 65051 num-packets 20
request-data-size 160
tos 128
frequency 30
ip sla schedule 1 start-time after 00:05:00
ip sla 2
udp-jitter 20.0.10.3 65052 num-packets 20 interval 10
request-data-size 20
tos 64
frequency 30
ip sla schedule 2 start-time after 00:05:05
On the target (destination) device:
ip sla responder
Additional References
Related Documents
Related Topic
Document Title
Cisco IOS commands
Cisco IOS Master Command List, All Releases
Cisco IOS IP SLAs commands
Cisco IOS IP SLAs Command Reference
MIBs
MIBs
• CISCO-RTTMON-MIB
• IPV6-FLOW-LABEL-MIB
MIBs Link
To locate and download MIBs for selected platforms,
Cisco IOS releases, and feature sets, use Cisco MIB
Locator found at the following URL:
http://www.cisco.com/go/mibs
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Configuring IP SLAs UDP Jitter Operations
Feature Information for IP SLAs UDP Jitter Operations
Technical Assistance
Description
Link
The Cisco Support and Documentation website
http://www.cisco.com/cisco/web/support/index.html
provides online resources to download documentation,
software, and tools. Use these resources to install and
configure the software and to troubleshoot and resolve
technical issues with Cisco products and technologies.
Access to most tools on the Cisco Support and
Documentation website requires a Cisco.com user ID
and password.
Feature Information for IP SLAs UDP Jitter Operations
The following table provides release information about the feature or features described in this module. This
table lists only the software release that introduced support for a given feature in a given software release
train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support.
To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 2: Feature Information for the IP SLAs UDP Jitter Operation
Feature Name
Releases
Feature Information
IP SLAs - UDP Jitter Operation
12.2(31)SB2
The IP SLAs User Datagram
Protocol (UDP) jitter operation
allows you to measure round-trip
delay, one-way delay, one-way
jitter, one-way packet loss, and
connectivity in networks that carry
UDP traffic.
12.2(33)SRB1
12.2(33)SXH
12.3(14)T
Cisco IOS XE Release 2.1
15.0(1)S
Cisco IOS XE 3.1.0SG
Cisco IOS XE Release 3.2SE
IP SLAs for IPv6 (UDP Jitter, UDP 12.2(33)SRC
Echo, ICMP Echo, TCP Connect) 12.2(33)SB
12.4(20)T
Cisco IOS XE Release 2.1
Cisco IOS XE 3.1.0SG
12.2(50)SY
Cisco IOS XE Release 3.2SE
IP SLAs Configuration Guide, Cisco IOS Release 15M&T
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Support was added for operability
in IPv6 networks.